Touch fastener part

ABSTRACT

1. Touch fastener part 
     2. A touch fastener part having a first substrate tape ( 10 ) having hooking elements ( 12 ) arranged on one side thereof, and having a second substrate tape ( 16 ) which, connected to the first substrate tape ( 10 ), has a connection means ( 20 ) on its side facing away from the hooking elements ( 12 ), wherein the second substrate tape ( 16 ) is wider than the first substrate tape ( 10 ) and at least one free lateral edge area ( 22 ) of the second substrate tape ( 16 ) projects beyond the adjacent longitudinal edge of the first substrate tape ( 10 ), and wherein the two substrate tapes ( 10,16 ) can be bent along and transversely to their longitudinal orientation, is characterized in that at least one free side edge area ( 22 ) of the second substrate tape ( 16 ) is provided with a weakening of resistance ( 27 ) in such a way that bending the two substrate tapes ( 10,16 ) transversely to their longitudinal orientation is facilitated.

The invention relates to a touch fastener part, having a first substratetape having hooking elements arranged on one side thereof and having asecond substrate tape which, connected to the first substrate tape, hasa connection means on its side facing away from the hooking elements,wherein the second substrate tape is wider than the first substrate tapeand at least one free lateral edge area of said second substrate tapeprojects beyond the adjacent longitudinal edge of the first substratetape and wherein the two substrate tapes can be bent along andtransversely to their longitudinal orientation.

Touch fastener parts have proved their value in many areas as adetachable and functionally reliable joining and fastening technology.For applications for aircraft or vehicle seats, they are used, amongother things, to fasten seat covers to foam body parts consisting of amolded foam, wherein the respective touch fastener parts are foamed intothe upholstery foam material during the manufacture of the respectiveseat and the respective other touch fastener parts having thecorresponding hooking elements are fixed, in particular sewn, to theupholstery cover material. During the production of the foam body parts,the touch fastener parts are inserted into so-called seating pipes of afoaming mold, and by placing foam material in the free cross-sections ofthe foaming mold, preferably by inserting polyurethane (PU) foam, thetouch fastener parts are attached to the foam body parts during thefoaming process. Document DE 10 2004 015 321 A1 discloses a touchfastener part of the genus mentioned above to be attached to foam bodyparts by a foaming process.

In the case of the known touch fastener part, both the substrate tape ofthe hooking elements and the second substrate tape are formed from aninjection-molded plastic section. The flat composite, formed by thetapes, has a relatively high resistance to bending, mainly in the planeof the tape. If, because of the shape of the foam body parts, curvedseam courses occur, wherein along said seam courses touch fastener partsare to be foamed, then one is forced to provide several touch fastenerparts of shorter length in bending areas instead of one continuous, longtouch fastener part have to be provided. This results at least in adisadvantageous increase in the amount of work required to attach thetouch fastener parts during the foaming process.

With regard to this problem, the invention addresses the object ofproviding a touch fastener part of the genus mentioned at the beginning,which permits being attached to the concerning foam body part during thefoaming process even in a curved shape.

According to the invention, this object is solved by a touch fastenerpart having the features of claim 1 in its entirety.

According to the characterizing part of claim 1, an essential feature ofthe invention is that at least one free side edge area of the secondsubstrate tape is provided with a weakening of resistance in such a waythat bending the two substrate tapes transversely to their longitudinalorientation is facilitated. The reduction in the bending stiffness ofthe touch fastener parts according to the invention and achieved in thisway permits the use of longitudinal touch fastener parts following thecourse of the seam, despite the connecting areas between the upholsterycover material and the foam body part concerned not running in astraight line.

The weakening of resistance is advantageously arranged at least at theone lateral edge area of the second substrate tape in the direction ofthe lateral edge area the two substrate tapes are bent.

The arrangement can advantageously be such that one side edge area eachof the second substrate tape protrudes beyond both longitudinal edges ofthe first substrate tape and that both side edge areas have the samesurface area and are each provided with an equally effective weakeningof resistance.

A particularly favorable bending behavior can be achieved if therespective weakening of resistance of a side edge area of the secondsubstrate tape continuously merges into the first substrate tape.

The arrangement can be particularly advantageous such that therespective weakening of resistance of the first and second substratetape ends at a bending line that defines the longitudinal axis of atleast the first substrate tape.

The arrangement can be particularly advantageous such that therespective weakening of resistance of the first and second substratetape subdivides the hooking elements of the first substrate tape intoadhesive segments which are aligned one behind the other along therespective bending line.

It is indispensable for the functionality of the touch fastener partsthat the hooking elements are protected against entry of foam materialduring the foaming process. In advantageous embodiments the twosubstrate tapes are provided with a preferably self-adhesive coversheeting on the sides of the hooking elements to prevent the hookingelements from sticking due to entering foam material and thus becominginoperative, and after the removal of said cover sheeting the hookingelements are exposed for hooking engagement.

A particularly reliable protection of the hooking elements against entryof foam material can be achieved if a foam barrier is inserted betweenthe cover sheeting and the hooking elements of the first substrate tape,wherein said foam barrier at least partially engages with the spacesbetween the hooking elements. A carpet pile, wherein the carrier of saidcarpet pile is in contact with the cover sheeting and the pile threadsof said carpet pile form an envelope for the hooking elements, may formsuch a foam barrier acting in addition to the cover sheeting.

The respective weakening of resistance may be formed by at least onereduction of wall thickness and/or perforation and/or recess and/orchange in strength of at least one side edge area of the secondsubstrate tape.

In the case of particularly advantageous embodiments, a sequence ofrecesses is formed, starting from at least one longitudinal edge of thesecond substrate tape, wherein said recesses extend transversely to thelongitudinal direction of the tape in both substrate tapes up to closeto the centerline of the tape or the bending line.

A particular increase in flexibility is achieved if a sequence ofrecesses is formed each starting from both longitudinal edges of thesecond substrate tape.

In particularly advantageous embodiments, the recesses are formedequally and have a V-shape tapering inwards from the respectivelongitudinal edges.

The arrangement can be made with particular advantage such that theboundary edges of the respective V-shaped recesses form an angle of 20°to 30°, preferably 25°, between each other.

The arrangement can be made with particular advantage such that therecesses are equidistantly spaced to each other at distances that arepreferably smaller than the width of the second substrate tape.

A particularly favorable bending behavior can be achieved if therecesses of the one sequence are aligned with the recesses of the othersequence.

In particularly advantageous embodiments, the arrangement is such thatthe recesses end in front of the centerline of the substrate tapes at adistance, which is less than ⅛, preferably less than 1/10, of the widthof the second substrate tape.

With particular advantage, the recesses can be formed from incisions orpunchings in the assignable tape material, wherein said incisions orpunchings extend completely through the material.

The arrangement can be made with advantage such that the V-shapedrecesses tapering in the direction of the bending line are closing onone side increasingly in the event of bending until the wall parts ofthe two substrate tapes, delimiting the V-shaped recesses, come intocontact with one another, and that, while in the event of bending in onedirection the assignable V-shaped recesses on one side are closing, therespective recesses on the opposite side of the two substrate tapesspread apart correspondingly.

According to claim 24, the subject matter of the invention is also theuse of a touch fastener part according to any one of claims 1 to 23 in afoaming mold, in particular for manufacturing of vehicle seat cushions,having a seating pipe into which the touch fastener parts can beinserted covered by the cover sheeting, wherein after connecting themolded foam to the connection means while forming at least a part of theseat cushion and after removal from the foaming mold after the coversheeting has been taken off, the hooking elements are exposed.

Below the invention is explained in detail with reference to embodimentsshown in the drawing. In the Figures:

FIG. 1 shows a representation, schematically simplified and not toscale, of a section of a seating pipe for a foaming mold, wherein atouch fastener part is inserted in the mold cavity of the seating pipeaccording to an embodiment of the invention;

FIG. 2 shows a representation, correspondingly simplified and enlargedby a factor of approx. 2.5 compared to a practical embodiment, of alength segment of the embodiment of FIG. 1, viewed towards the tape sidehaving the hooking elements and without any overlying cover sheeting;

FIG. 3 shows a representation corresponding to FIG. 2 of the top view ofthe embodiment, wherein a bent state is shown;

FIG. 4 shows a representation, simplified and not to scale, of a secondembodiment of the touch fastener part according to the invention,wherein the state before attaching a cover sheeting is shown;

FIG. 5 shows a representation, schematically simplified corresponding toFIG. 1 and not to scale, of a section of a seating pipe for a foamingmold, wherein a touch fastener part is inserted in the mold cavity ofthe pipe according to a third embodiment of the invention; and

FIG. 6 shows a representation corresponding to FIG. 4 of the thirdembodiment of the touch fastener part, wherein the state before thecover sheeting is attached is shown.

In FIG. 1, a seating pipe, which is part of a foaming mold that is notshown apart from that, is denoted by 2. The seating pipe 2 has a moldcavity 4 in the form of a recess, the free cross-section of said recessis adapted to the touch fastener part 6 to be received therein. Alongthe lateral longitudinal edges the mold cavity 4 is delimited by flatwall sections 8. The touch fastener part 6 has a flat substrate tape 10,on one side of said substrate tape 10 hooking elements are arranged. Inthe example shown, these are formed by mushroom heads 12 (only part ofwhich are numbered in the drawing), which are located on stemsprojecting from the substrate tape 10. This can be a so-called touchfastener element, in which 200 to 400 or more hooking elements percm²are provided on a substrate tape 10. It can be formed by a polyamidebase fabric having polypropylene stems, on said stems the mushroom heads12 are formed by thermal processing. The substrate 10 having themushroom heads 12 can also consist of an injection-molded plasticsection. While in the example shown, the hooking elements are formed bymushroom heads 12, the hooking elements can also be formed by slings orloops of a loop material. Touch fastener elements of this type, havingmushroom heads 12 as hooking elements, are commercially available by theapplicant under the product name Pressotex® and having hooking elementsin the form of a fleece material under the product name Klettostar®.

On its side facing away from the hooking elements, the substrate tape 10is firmly connected to a second substrate tape 16 via an adhesive layer14. In this example, the adhesive layer 14 consists of a moisturecross-linking adhesive containing polyurethane. An iron wire 18 isembedded in the center of the adhesive layer 14 and extends over theentire length of the touch fastener part 6, perpendicular to the drawingplane. In conjunction with permanent magnetic elements (not shown) inthe foaming mold, the iron wire 18 forms a magnetic holding devicefixing the touch fastener part 6 in the seating pipe 2. The secondsubstrate tape 16, attached via the adhesive layer 14, is aninjection-molded plastic section having round protrusions 20 in the formof free-standing rods formed on the side facing away from the adhesivelayer 14. These form a connecting means that ensures for good adhesionof the molded foam during the foaming process. As can be seen in thedrawing, the second substrate tape 16 has a greater width than the firstsubstrate tape 10 and a side edge area 22 each, which have the samewidth, of the second substrate tape 16 protrudes laterally beyond thefirst substrate tape 10. With the side facing away from the projections20, these edge areas 22 each form a connecting zone 24, to which a coversheeting 26 can be attached in a detachable manner. In this example, thecover sheeting 26 is formed by a sheeting, for instance made ofpolyester, which is provided in the manner of an adhesive tape with apressure-sensitive adhesive 28, and the longitudinal edges of the coversheeting are detachably glued by said adhesive 28 to the connectingzones 24 of the side edge areas of the second substrate tape 16. FIG. 1shows this state in which, in preparation for a foaming process, thetouch fastener part 6 together with the cover sheeting 26 are insertedin the seating pipe 2, wherein said cover sheeting tightly encloses theentire area of the hooking elements (mushroom heads 12) and protectsthem against the entry of molding foam during the foaming process. Afterremoving the cover sheeting 26, the mushroom heads 12 are available infully functional state for the subsequent establishment of the adhesiveconnection with the respective corresponding further touch fastenerpart.

FIG. 2 shows a top view of a length segment of the embodiment of thetouch fastener part 6 of FIG. 1 after the detachable cover sheeting 26has been removed. As shown, starting from the longitudinal edgesdesignated 25 of the second substrate tape 16, recesses 27 are formed,which extend in both tapes 16 and 10 in a direction perpendicular to thelongitudinal direction of the tape up to close to the centerline of thetape. More precisely, the recesses 27 each end equidistantly from theembedded iron wire 18 running in the centerline of the tape. In theexample shown, the distance between the inner ends of the recesses 27and the centerline of the tape is smaller than 1/10 of the width of thesecond substrate tape 16. The identically formed recesses 27 of bothlateral sequences are equally formed and are arranged in alignment witheach other and each have a V-shape, wherein the width of said V-shapedecreases from the outer longitudinal edge (25 in FIG. 1) inwards andends in a tip. The spacing between the equidistantly arranged recesses27 is equal to the width of the second substrate tape 16 or preferablyslightly less than that.

As mentioned above, mainly due to the material properties of the secondsubstrate tape 16 formed by a plastic section, the touch fastener part 6has a relatively high stiffness against bending in the tape plane, i.e.in the plane of FIG. 2. The recesses 27 result in a considerablereduction of this stiffness and provide sufficient flexibility to allowthe touch fastener part 6 to be arranged in a course deviating from thestraight line.

In this respect, FIG. 3 shows the example of a length segment having acurved course, wherein the longitudinal direction of the tape is angledby approximately 90°. Due to the fact that the recesses 27, because ofthe V-shape, form material cutouts having a larger width at thelongitudinal edges, there are free spaces available on the inside atbends, as shown in FIG. 3, which allow the walls of the recesses 27 toapproach each other while tapering the V-shape, while the V-shapespreads apart on the outside of the bend. As a result, tighter bends,such as those shown in FIG. 3, can be achieved without bulging.

FIG. 4 shows a second embodiment, wherein however, unlike in FIG. 1, thetouch fastener part is shown in a partially finished state. Theembodiment of FIG. 4 corresponds to the embodiment of FIGS. 1 to 3,apart from the fact that the pressure-sensitive adhesive 28 of the coversheeting 26 is not in direct contact with the mushroom heads 12, butthat a protective layer 38 is applied to the adhesive 28. The protectivelayer 38 is formed by a sheeting, for example of polyester, wherein thewidth of the sheeting corresponds to the width of the first substratetape 10. In the partially finished state of FIG. 4, the protective layer38 of the cover sheeting 26 is in contact with the mushroom heads 12,but not yet glued to the connecting zones 24 of the edge areas 22 of thesecond substrate tape 16 by moving the side edges of the cover sheeting26 as indicated by arrows 36. The protective layer 38 extending over theentire width of the first substrate tape 10 protects the mushroom heads12 from an application of the pressure-sensitive adhesive 28 of thecover sheeting 26.

FIGS. 5 and 6 illustrate a third embodiment in which, in contrast to theembodiments described above, an additional foam barrier is provided toprotect the mushroom heads 12 from entering of molding foam during thefoaming process. This foam barrier is formed by a carpet pile, whereinthe carrier 52 of the carpet pile, instead of the protective layer 38,rests on the pressure-sensitive adhesive 28 of the cover sheeting 26 andis glued to the cover sheeting 26. The pile threads 53 of the carpetpile form a wrapping of the mushroom heads 12 as an additional foambarrier. At the same time, the carrier 52 protects the mushroom heads 12from contact with the pressure-sensitive adhesive 28. FIG. 6 shows,corresponding to FIG. 4, the partially finished state before the coversheeting 26 is glued to the connecting zones 24 at the edge areas 22 ofthe second substrate tape 16.

1. A touch fastener part having a first substrate tape (10) havinghooking elements (12) arranged on one side thereof, and having a secondsubstrate tape (16) which, connected to the first substrate tape (10),has a connection means (20) on its side facing away from the hookingelements (12), wherein the second substrate tape (16) is wider than thefirst substrate tape (10) and at least one free lateral edge area (22)of the second substrate tape (16) projects beyond the adjacentlongitudinal edge of the first substrate tape (10), and wherein the twosubstrate tapes (10, 16) can be bent along and transversely to theirlongitudinal orientation, characterized in that at least one free sideedge area (22) of the second substrate tape (16) is provided with aweakening of resistance (27) in such a way that bending the twosubstrate tapes (10, 16) transversely to their longitudinal orientationis facilitated.
 2. The touch fastener part according to claim 1,characterized in that the weakening of resistance is arranged at leastat the one lateral edge area (22) of the second substrate tape (16), inthe direction of the lateral edge area (22) the two substrate tapes (10,16) are bent.
 3. The touch fastener part according to claim 1,characterized in that one side edge area (22) each of the secondsubstrate tape (16) protrudes beyond both longitudinal edges of thefirst substrate tape (10) and that both side edge areas (22) have thesame surface area and are each provided with an equally effectiveweakening of resistance (27).
 4. The touch fastener part according toclaim 1, characterized in that the respective weakening of resistance ofa side edge area (22) of the second substrate tape (16) continuouslymerges into the first substrate tape (10).
 5. The touch fastener partaccording to claim 1, characterized in that the respective weakening ofresistance (27) of the first (10) and second substrate tape (16) ends ata predetermined distance from a bending line defining the longitudinalaxis (18) of at least the first substrate tape (10).
 6. The touchfastener part according to claim 1, characterized in that the respectiveweakening of resistance (27) of the first (10) and the second substratetape (16) subdivides the hooking elements (12) of the first substratetape (10) into touch fastener segments, which are arranged in an insularmanner and which are aligned one behind the other at the respectivebending line, and that the hooking elements (12) continuously extendpast the assignable weakening of resistance (27) in a longitudinal tapefrom touch fastener segment to touch fastener segment along the bendingline.
 7. The touch fastener part according to any one of the precedingclaim 1, characterized in that the two substrate tapes (10, 16) aredivided into the individual insular touch fastener segments, which areinterconnected adjacent to one another at the points of weakening ofresistance (27) along the bending line via articulation points formed insuch a way that both the hooking elements (12) and the connection means(20) extend from one touch fastener segment to the adjacent touchfastener segment beyond the assignable articulation points.
 8. The touchfastener part according to claim 1, characterized in that the twosubstrate tapes (10, 16) are provided with a preferably self-adhesivecover sheeting (26) on the sides of the hooking elements (12), whereinafter removal of said cover sheeting (26) the hooking elements (12) areexposed for hooking engagement.
 9. The touch fastener part according toclaim 1, characterized in that a foam barrier (52, 53) is insertedbetween the cover sheeting (26) and the hooking elements (12) of thefirst substrate tape (10), wherein said foam barrier (52, 53) at leastpartially engages with the spaces between the hooking elements (12). 10.The touch fastener part according to claim 1, characterized in that therespective weakening of resistance is formed by at least one reductionof wall thickness and/or perforation and/or recess (27) and/or change instrength of at least one side edge area (22) of the second substratetape (16).
 11. The touch fastener part according to claim 1,characterized in that a sequence of recesses (27) is formed, startingfrom at least one longitudinal edge (25) of the second substrate tape(16), wherein the recesses (27) extend transversely to the longitudinaldirection of the tape in both substrate tapes (10, 16) up to close tothe centerline (18) of the tape or the bending line.
 12. The touchfastener part according to claim 1, characterized in that a sequence ofrecesses (27) is formed each starting from both longitudinal edges (25)of the second substrate tape (16).
 13. The touch fastener part accordingto claim 1, characterized in that the recesses (27) are formed equallyand have a V-shape tapering inwards from the respective longitudinaledge (25).
 14. The touch fastener part according to claim 1,characterized in that the boundary edges of the respective V-shapedrecesses (27) form an angle of 20° to 30°, preferably 25°, between eachother.
 15. The touch fastener part according to claim 1, characterizedin that the recesses (27) are equidistantly spaced to each other atdistances that are preferably smaller than the width of the secondsubstrate tape (16).
 16. The touch fastener part according to claim 1,characterized in that the recesses (27) of one sequence are aligned withthe recesses (27) of the other sequence.
 17. The touch fastener partaccording to claim 1, characterized in that the recesses (27) end infront of the centerline (18) of the substrate tapes (10, 16) at adistance which is less than ⅛, preferably less than 1/10, of the widthof the second substrate tape (16).
 18. The touch fastener part accordingto claim 1, characterized in that the recesses (27) are formed byincisions or punchings in the assignable tape material, wherein saidincisions or punchings extend completely through the material.
 19. Thetouch fastener part according to claim 1, characterized in that theV-shaped recesses (27) tapering in the direction of the bending line areclosing increasingly on one side, in the event of bending, until thewall parts of the two substrate tapes (10, 16), delimiting the V-shapedrecesses (27), come into contact with one another.
 20. The touchfastener part according to claim 1, characterized in that while in theevent of bending in one direction the assignable V-shaped recesses (27)on one side are closing, the respective recesses (27) on the oppositeside of the two substrate tapes (10, 16) spread apart correspondingly.21. The touch fastener part according to claim 1, characterized in thatthe weakening of resistance (27) subdivides the two substrate tapes (10,16) into individual touch fastener segments, which are interconnected toeach other at the point of weakening of resistance, and that theconnection means (20) extend from touch fastener segment to touchfastener segment across the assignable weakening of resistance.
 22. Thetouch fastener part according to claim 1, characterized in that thefirst substrate tape (10), having its connection means (20), is free ofweakenings of resistance in a longitudinal strip between the toughfastener segments.
 23. The touch fastener part according to claim 1,characterized in that the recesses (27) on both sides of the tapes (10,16) are formed equally and are arranged in alignment with one anotherand each have a V-shape, wherein the width of the V-shape decreasesinwards from the outer longitudinal edge (25) and ends in the tip. 24.The use of a touch fastener part according to claim 1 in a foaming mold,in particular for manufacturing of vehicle seat cushions, having aseating pipe (2) into which the touch fastener parts (6) can be insertedcovered by the cover sheeting (26), wherein after connecting of themolded foam to the connection means (20) while forming at least a partof the seat cushion and after removal from the foaming mold afterremoving the cover sheeting (26), the hooking elements (12) are exposed.